Beverages and foodstuffs resistant to light induced flavor changes, processes for making the same, and compositions for imparting such resistance

ABSTRACT

One aspect of the present invention is concerned with a composition comprising caramelised carbohydrate, which composition, when dissolved in water at a dry solids content of 0.1 wt. %, exhibits: i. an absorption at 280 nm (A 280 ) that exceeds 0.01, preferably exceeds 0.05, more preferably exceeds 0.1 and most preferably exceeds 0.3; and ii. an absorption ratio A 280/560  of at least 200, preferably of at least 250. Other aspects of the invention relate to a method of manufacturing a beverage or foodstuff that is resistant to light induced flavour changes, said method comprising introducing into said beverage or foodstuff a composition as defined above; and to a process for the manufacture of said composition.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a beverages and foodstuffs havingheightened resistance to light induced flavour changes, and compositionsthat can be used advantageously as additives in beverages or foodstuffsto prevent or reduce light induced flavour changes. The products andcompositions according to the invention contain caramelised carbohydrateof low colour intensity. The present invention is particularly suitablefor use in beverages or foodstuffs that are prone to developing anoff-flavour as a result of exposure to light, and especially in suchbeverages or foodstuffs that are not adequately protected from thedetrimental impact of light by their packaging.

The present invention also includes a process for the manufacture ofsuch beverages and foodstuffs, using such compositions.

BACKGROUND OF THE INVENTION

Light induced off-flavour formation is a well known problem in thebeverage and food industry. A variety of off-flavour generatingreactions that are initiated or accelerated by exposure to light havebeen described in the scientific literature. The rate at which theseoff-flavour generating reactions progress is usually increaseddramatically by exposure to light with a wavelength below 500 nm,particularly UV-light.

Light sensitive flavour changes in beverages and foodstuffs may beinhibited effectively by packaging these beverages or foodstuffs in amaterial that will not transmit light frequencies that promoteoff-flavour generating reactions. However, for a variety of reasons itis sometimes desirable to employ a packaging material that does notexhibit this light shielding quality. In those cases, the composition ofthe beverage or foodstuff will need to be optimised to achievesufficient stability against light induced flavour changes. Where thiscannot be achieved with the usual constituents of such beverages orfoodstuffs, special light stabilising additives may be used.

It is known in the art to employ a large variety of additives for thestabilisation of beverages and food products against light inducedoff-flavour formation. Many of these additives derive theireffectiveness from their capability to inhibit off-flavour generatingreactions, e.g. by scavenging of one or more of the reactants and/or keyintermediates. In addition, additives have been proposed that scavengethe off-flavour causing reaction products (e.g. by forming anon-volatile complex) or that promote degradation of these reactionproducts to less odorous products.

Instead of minimising the impact of light induced off-flavour generatingreactions as described above, it is also possible to prevent thesereactions from occurring by introducing an additive that neutralises theundesired impact of said light and particularly the ultravioletcomponent of said light. U.S. Pat. No. 5,948,458 describes a method forthe prevention of spoilage, rancidity or off-color in a liquid foodproduct containing unsaturated lipids and fats caused by exposure of theliquid food product to ultraviolet light comprising the step of addingto said food product an ultraviolet absorbing effective amount oftricalcium phosphate.

U.S. Pat. No. 4,389,421 teaches the addition of organic compoundscontaining 1,8-epoxy groups, such as 1,8-cineole, to prevent orsignificantly reduce light struck flavour in malt beverages. It ishypothesised therein that the addition of 1,8-epoxy compounds to maltbeverages prevents the formation of methyl butenyl mercaptan bypreventing cleavage of a five carbon fragment (iso-pentenyl chain) fromthe iso-hexenoyl side chain of iso-α-acids, which fragments wouldotherwise react with the sulfhydryl group forming the iso-pentenylmercaptan (methyl butenyl mercaptan). It is stated that the 1,8-epoxycompounds may prevent formation of methyl butenyl mercaptan by reactingwith the iso-pentenyl fragment or by protecting the iso-hexenoyl sidechain from fragmenting or by blocking the sulfhydryl group from reactingwith the iso-pentenyl fragment.

Many food additives that have been proposed for stabilising beverages orfoodstuffs against light induced off-flavour formation have to belabelled as chemical or artificial entities on the product package. Witha view to consumer acceptance manufacturers of beverages and foodstuffsgenerally do not like to use such chemical additives but, instead,prefer to employ additives that make more appealing ingredient labels(consumer-friendly labels) possible and that deliver similarfunctionality.

SUMMARY OF THE INVENTION

The inventors have discovered that improved resistance to light inducedflavour changes may be imparted to beverages and foodstuffs bycompositions that comprise caramelised carbohydrate of low colourintensity. The use of caramelised carbohydrate, such as caramel, offersthe advantage that the present composition may be referred to on productpackaging ingredient lists by a consumer-friendly term, e.g. “caramel”,“caramel colour”, “caramel extract” or “caramel isolate”.

The inventors have unexpectedly discovered that caramelisation, i.e. thereaction occurring when carbohydrates are heated, yields reactionproducts exhibiting the capability to absorb ultraviolet light withoutbeing decomposed into undesirable off-flavour generating substances,especially if the carbohydrates are caramelised in the presence of anitrogen source. More importantly, the inventors have found that theseUV-absorbing substances, unlike other intrinsic constituents ofcaramelised materials, are essentially colourless. Thus, based on thisknowledge, the inventors have developed a composition that can be usedto stabilise beverages or foodstuffs against light induced flavourchanges without introducing a substantial colour change. Although theinventors believe that the advantageous properties of the presentcomposition are mainly associated with its UV-absorbing properties, itis possible that the protective properties of the present compositionare partially derived from other qualities.

The present products and light stabilising compositions containcaramelised carbohydrate of low colour intensity and combines arelatively high absorption of UV light, particularly at wavelengths inthe range of 250 to 400 nm, with a relatively low absorption of visiblelight, as demonstrated by a ratio of the light absorption at wavelengths280 nm and 560 nm (A_(280/560)) of at least 200. The caramelisedcarbohydrate of low colour intensity is suitably prepared bydecolourising caramel to remove the components responsible for the browncolour whilst retaining the UV absorbing components, as demonstrated byan increase of A_(280/560) by at least 100%. Alternatively, thecaramelised carbohydrate may be prepared by selecting reactionconditions that favour formation of the UV absorbing components (e.g.pyrazines) over formation of colour imparting components (e.g.melanoidins).

Commercially available caramels that have been produced bycaramelisation in the presence of a nitrogen source are commonlycharacterised on the basis of the so called extinction ratio (theabsorption ratio A_(280/560)) which is determined by the methoddescribed below under “Classification/Absorbance ratio”. Typically,these caramels exhibit an absorption ratio A_(280/560) of less than 120.Decolourisation of caramels in accordance with the present inventionremoves coloured components that absorb at around 560 nm whilst at thesame time retaining its UV-absorption characteristics. Thus,decolourisation of caramels in accordance with the invention produces amaterial with a significantly higher absorption ratio A_(280/560) thanordinary caramels that have been produced by caramelisation in thepresence of a nitrogen source (notably ammonia caramel and sulphiteammonia caramel).

DETAILED DESCRIPTION OF THE INVENTION

Accordingly, one aspect of the present invention is concerned with acomposition comprising caramelised carbohydrate, which composition, whendissolved in water at a dry solids content of 0.1 wt. %, exhibits:

-   -   i. an absorption at 280 nm (A₂₈₀) that exceeds 0.01, preferably        exceeds 0.05, more preferably exceeds 0.1 and most preferably        exceeds 0.3; and    -   ii. an absorption ratio A_(280/560) of at least 200, preferably        of at least 250.

The caramelised carbohydrate of the invention differs from ordinarycaramels by its relatively low content of colour components, notablybrown colour components. The low content of colour components is evidentfrom the relatively low absorption at 560 nm (A₅₆₀). At the same time,the caramelised carbohydrate exhibits strong UV absorption capacity asevidenced by the present composition's A₂₈₀. Thus, the presentcaramelised carbohydrate as well as the present composition arecharacterised by a relatively high absorption ratio A_(280/560). Thepresent composition typically contains at least 10%, preferably at least20%, more preferably at least 30%, even more preferably at least 40% andmost preferably at least 50% of the caramelised carbohydrate by weightof dry solids.

The A₂₈₀ is determined relative to % solids as described herein belowunder “Colour intensity”, except that the absorbance is measured at 280nm instead of 610 nm.

The term “wavelength” as used in here, refers to a wavelength of light,unless indicated otherwise. Whenever reference is made in here to“absorption”, unless indicated otherwise, this refers to absorption oflight.

Caramelisation is commonly defined as the thermal degradation of sugarsleading to the formation of volatiles (caramel aroma) and brown-colouredproducts (caramel colours). The process is acid or base catalysed andgenerally requires temperature in excess of 120° C. at a pH within therange of 3 and 9. The generation of flavours and colours in thermallyinduced caramelisation requires that sugars, normally monosaccharides,first undergo intramolecular rearrangements. Usually, the reactioncauses the release of H⁺. Thus, the pH of a solution undergoingcaramelisation falls with time.

Caramelisation occurs in a complex sequence of reactions. The initialenolisation reaction is of particular importance because it initiatesthe subsequent chain of events. These reactions give rise to sugardegradation products which can react further to produce oxygenheterocyclic and carbocyclic compounds via aldol condensation. The keyintermediates of the themal caramelisation are the osuloses. These areα-dicarbonyl compounds such as 3-deoxyhexosulose. These substances notonly lead to the formation of caramel colour but also give rise to theimportant volatile products which are typical of caramel flavour.

The inventors have discovered that caramelised carbohydrates, andespecially caramels obtained by caramelisation in the presence of anitrogen source are particularly suitable for use in accordance with thepresent invention. Caramels so obtained are characterised by thepresence of significant quantities of cyclic nitrogen containingcomponents, such as pyrazine derivatives. The inventors have observed astrong positive correlation between the effectiveness of the presentcomposition in stabilising beverages and foodstuffs against lightinduced flavour changes and its content of N-heterocyclic substances. Ina preferred embodiment, the present composition contains at least 0.5%,preferably at least 1.0%, more preferably at least 3.0% by weight of drymatter, of N-heterocyclic substances. It was found that N-heterocyclicsubstances of which the ring(s) contains at least two nitrogen atomsexhibit particularly good light stabilising properties. AromaticN-heterocyclic substances, particularly those containing two nitrogenatoms, are particularly preferred. Preferably, the N-heterocyclicsubstances are selected from the group consisting of pyrazines,pyrimidines, pyridazines, and combinations thereof.

The N-heterocyclic substances according to the present inventionpreferably exhibit a water solubility of at least 10 mg/kg, morepreferably of at least 100 mg/kg. The molecular weight of saidsubstances typically does not exceed 500, preferably it does not exceed400, more preferably it does not exceed 350.

The inventors have observed that the present composition producesparticularly good results if the caramelised carbohydrate contains asignificant amount of pyrazine derivatives, particularly pyrazinederivatives that comprise carbohydrate derived substituents.Accordingly, in a particularly preferred embodiment, the presentcomposition contains at least 0.5%, preferably at least 1.0%, morepreferably at least 3.0% by weight of dry matter, of pyrazinederivatives according to formula (I):

wherein R₁—R₄ independently represent hydrogen; a hydroxyhydrocarbylresidue; an ester of a hydroxyhydrocarbyl residue; or an ether of ahydroxyhydrocarbyl residue; and at least one of R₁—R₄ is ahydroxyhydrocarbyl residue or an ester or an ether thereof. Preferably,at least one of R₁—R₄ represents a hydroxyhydrocarbyl residue or anester thereof, more preferably it represents a hydroxyhydrocarbylresidue.

The present invention encompasses all stereoisomers that can berepresented by the formulas presented herein. Thus, the presentinvention may employ racemic mixtures of the present N-heterocyclicsubstances as well as essentially pure enantiomers of said substances.

In a particularly preferred embodiment, at least two of R₁—R₄ is ahydroxyhydrocarbyl residue or an ester or an ether thereof. In case thepyrazine derivative contains two hydroxyhydrocarbyl residues, it ispreferred that these residues are in the para or meta positions. Mostpreferably, in the present pyrazine derivatives two of R₁—R₄ are ahydroxyhydrocarbyl residue or an ester or an ether thereof

The term “hydroxyhydrocarbyl” as used herein refers to hydroxylsubstituted hydrocarbyls. The term “hydrocarbyl” refers to branched andlinear hydrocarbon chains, optionally containing one or more unsaturatedcarbon-carbon bonds, i.e. carbon-carbon double bonds and carbon-carbontriple bonds, said hydrocarbon atoms preferably having 1-20 carbonatoms. Typical examples of hydroxyhydrocarbyls include branched as wellas unbranched hydroxyalkyls and hydroxyalkenyls. In addition to hydroxylsubstituents, the hydroxycarbyl residue may also comprise othersubstituents such as carbonyl, carboxyl, acyl, amino, acylamino, alkoxy,hydroxyamino, alkoxyamino, thiol, disulfide, ether, ester, alkylthio andamide groups. Preferably, the latter substituents contain not more than10, more preferably not more than 5 carbon atoms. Most preferably, thehydrocarbyl residue does not contain substituents other than one or morehydroxyl groups.

Typically, the hydroxyhydrocarbyl residue comprises 1-10, preferably 2-4carbon atoms, and more preferably 3 or 4 carbon atoms. In a particularlypreferred embodiment, the total number of carbon atoms present in thepyrazine derivatives is within the range of 5-12, more preferably withinthe range of 9-12.

The at least one hydroxyhydrocarbyl residue preferably comprises atleast two hydroxyl groups. More preferably, said residue comprises threeor four hydroxyl groups.

The pyrazine derivatives in the light stabilising composition of thepresent invention typically contain a high fraction of di-substitutedpyrazines. Hence, in a preferred embodiment, the present compositioncontains at least 0.5% by weight of dry matter of pyrazine derivativesaccording to formula (I), wherein at least two of R₁—R₄ independentlyrepresent a hydroxyhydrocarbyl residue or an ester or an ether thereof.

Examples of di-substituted pyrazine derivatives that are particularlyabundant in the present composition include fructosazines, particularly2,5- and 2,6-substituted fructosazines. Hence, in a preferredembodiment, the present composition contains at least 0.1%, morepreferably at least 0.3%, even more preferably at least 0.5% and mostpreferably at least 1.0% of a fructosazine selected from the groupconsisting of 2,5-deoxyfructosazine(1-[5-(2,3,4-trihydroxybutyl)-pyrazin-2-yl]-butane-1,2,3,4-tetraol),2,6-deoxyfructosazine(1-[6-(2,3,4-trihydroxybutyl)-pyrazin-2-yl]-butane-1,2,3,4-tetraol),2,5-fructosazine(1-[5-(1,2,3,4-tetrahydroxybutyl)-pyrazin-2-yl]-butane-1,2,3,4-tetraol),2,6-fructosazine(1-[6-(1,2,3,4-tetrahydroxybutyl)-pyrazin-2-yl]-butane-1,2,3,4-tetraol)and combinations thereof, by weight of dry matter. In an especiallypreferred embodiment, the fructosazine is selected from the groupconsisting of 2,5-deoxyfructosazine, 2,6-deoxyfructosazine andcombinations thereof. Most preferably, the fructosazine is selected fromthe group consisting of1-[6-(2,3,4-trihydroxybutyl)-pyrazin-2-yl]-butane-1,2,3,4-tetraol,1-[5-(2,3,4-trihydroxybutyl)-pyrazin-2-yl]-butane-1,2,3,4-tetraol andcombinations thereof. The latter deoxyfructosazines are represented bythe following formulae:

-   1-[6-(2,3,4-trihydroxybutyl)-pyrazin-2-yl]-butane-1,2,3,4-tetraol    (2,6-deoxyfructosazine)-   1-[5-(2,3,4-trihydroxybutyl)-pyrazin-2-yl]-butane-1,2,3,4-tetraol    (2,5-deoxyfructosazine)

The present invention encompasses the use in beverages or foodstuffs ofboth synthetic (artificial) and natural pyrazine derivatives, the latterbeing most preferred. Here the term “natural” is used to indicate thatsuch a pyrazine derivative is obtained from a natural source, i.e. it isnot obtained by reaction of (petro)chemicals.

The present composition, when obtained by caramelising sugars in thepresence of a nitrogen source, will usually contain a significant amountof aminosugars such as glucosamine and fructosamine. More particularly,the composition will typically contain at least 0.001%, preferably atleast 0.01%, more preferably at least 0.03%, most preferably at least0.05% aminosugars, particularly aminosugars comprising mono- ordisaccharide residues, more particularly aminosugars comprising amonosaccharide residue. The latter percentages being calculated as % byweight on dry matter of the composition.

The present composition is suitable for stabilising a wide variety ofbeverages and food products against light induced flavour changes. Bestresults, however, are obtained in water containing food products,particularly water-continuous food products. In order to avoid that theuse of the present composition in these products will causeprecipitation, it is preferred that the present stablising compositionis essentially completely water soluble. Preferably, the presentcomposition is essentially completely water soluble up to a dry solidscontent of at least 0.01 wt. %, more preferably up to a dry solidscontent of at least 0.05 wt. %, most preferably of at least 0.1 wt. %.

The present light stabilising composition contains not more than minoramounts of the melanoidins that are largely responsible for the browncolour of caramelised materials. Melanoidins are relatively largemolecules that can suitably be removed after completion of thecaramelisation reaction by means of filtration or another separationtechnique that enables separation on the basis of molecular weight,size, hydrophobicity or charge. The resulting composition typicallycontains less than 30%, preferably less than 20%, more preferably lessthan 15%, even more preferably less than 10% and most preferably lessthan 5%, by weight of dry matter, of components having a molecularweight in excess of 30 kDa. More particularly, the aforementionedamounts relate to the components having a molecular weight in excess of10 kDa, even more particularly in excess of 5 kDa and most particularlyin excess of 1 kDa. The amount of components with a molecular weight inexcess of 30 kDa contained in the present composition is determined bypassing an aqueous solution of said composition over a Millipore® YM30filter. Millipore® YM10 aid YM1 filters may be used to determinecontents of components with a molecular weight in excess of 10 kDa and 1kDa respectively. It is noted that different techniques for determiningthe content of high molecular components may yield different results.Therefore, it should be understood that the kDa numbers recited withinthis application are defined in relation to the methodology describedabove.

The reduced level of melanoidins and other colour contributingsubstances is also evident by a low colour intensity, particularly atwavelengths around 600 nm. In a particularly preferred embodiment of theinvention, the present light stabilising composition has a colourintensity at 610 nm that does not exceed 0.024, preferably does notexceed 0.01 as calculated herein. Even more preferably, said colourintensity does not exceed 0.003 as calculated herein. A suitable methodfor determining the colour intensity at 610 nm is described below.

The present composition is advantageously provided in a relativelyconcentrated form, e.g. with a solids content of at least 10 wt. %. Morepreferably, the solids content is at least 20 wt. %, most preferably atleast 30 wt. %. The present composition may take the form of a liquid, asyrup, a paste, a powder, granules or tablets. Preferably, the presentcomposition contains less than 80 wt. %, more preferably less than 70wt. % water.

As explained above, the present composition suitably contains nitrogensubstances. Preferably, however, the amount of nitrogen substances inthe present composition is limited. Consequently, in a preferredembodiment, the total nitrogen content of the present composition, asdetermined by Nitrogen Determination (Kjeldahl Method), Method II (FNP5), is less than 20%, more preferably less than 15%, most preferablyless than 10% by weight of dry matter. In another preferred embodiment,said nitrogen content is at least 0.1%, more preferably at least 0.2% byweight of dry matter.

The light stabilising composition according to the invention maysuitably include additives such as anti-oxidants, emulsifiers andcarrier materials. Preferably, however, the present composition does notcontain any ingredients that are not considered “natural”, i.e. thatneed to be labelled as “artificial”, “synthetic” or “chemical”. In aparticularly preferred embodiment the entire present composition can belabelled as “caramel”, “caramel colour”, “caramel isolate”, “caramelextract” or the like.

Another aspect of the present invention is concerned with the use of thepresent light stabilising composition as an additive to prevent orreduce light induced flavour changes in beverages or foodstuffs.Typically, the present composition is introduced into the beverage orfoodstuff in an amount of at least 0.01 wt. %, preferably of at least0.02 wt. % and more preferably of at least 0.03 wt. %, calculated on thebasis of the amount of dry matter introduced. Typically the amountintroduced will not exceed 1 wt. %, preferably it will not exceed 0.5wt. %, more preferably it will not exceed 0.3 wt. %, again calculated onthe basis of the amount of dry matter introduced.

The present composition is particularly suitable for preventing lightinduced flavour changes in beverages and foodstuffs that containsignificant quantities of riboflavin, which substance can act as aphoto-initiator. The composition is particularly advantageously used inbeverages and foodstuffs that contain at least 10 μg/kg (ppb)riboflavin, more preferably at least 50 μg/kg riboflavin and mostpreferably at least 100 μg/kg riboflavin.

As mentioned herein before, the light stabilising composition accordingto the invention advantageously contains substantial amounts of pyrazinederivatives. Typically, the present composition is introduced intobeverages or foodstuffs in such an amount that the resulting productcontains at least 0.5 mg/kg preferably at least 1 mg/kg, more preferablyat least 3 mg/kg and most preferably at least 10 mg/kg of the pyrazinederivatives as defined herein before. In an even more preferredembodiment, the malt beverage contains at least 0.5 mg/kg, preferably atleast 1 mg/kg of a fructosazine selected from the group consisting of2,5-deoxyfructosazine, 2,6-deoxyfructosazine, 2,5-fructosazine,2,6-fructosazine and combinations thereof.

The benefits of the present light stabilising composition areparticularly pronounced if said composition is used to stabilise bottledbeverages. The term “bottled beverage” encompasses beverages in glasscontainers (e.g. bottles, jars etc.) as well as beverages inlight-transparent plastics, such as plastics based on polyethylene (e.g.polyethylene (PE), polyethylene teraphthalate (PET) and/or polyethylenenaphthalate PEN)); polycarbonate; PVC; and/or polypropylene. In aparticularly preferred embodiment, the present light stabilisingcomposition is used as an additive, particularly a light stabilisingadditive, in beverages bottled in green, clear (e.g. flint) or blueglass. Most preferably, it is used as an additive in beverages bottledin green or clear glass.

The present invention encompasses the use of the light stabilisingcomposition in a wide variety of beverages, including beer, soft drinks,liquor, juices, dairy drinks etc. In a particularly preferredembodiment, the composition is used to prevent or reduce light inducedflavour changes in malt beverages, such as beer, ale, malt liquor,porter, shandy, and others which are made from or contain fermentedextracts of malt. The present light stabilising composition isparticularly advantageously employed to improve light stability of beer,more preferably of relatively pale beer, e.g. beer with an EBC colourvalue of less than 25, more preferably of less than 15, most preferablyof less than 12. A suitable method for determining the EBC colour valueis described below.

It is well known in the brewing industry that exposure of brewedbeverages, such as lager, ale, porter, stout and the like (hereingenerically referred to as “beer”), to sunlight or artificial light, hasa detrimental effect on the sensory quality of these beverages. To bemore precise, exposure to light is known to cause the development of theso-called “skunky” flavour, which is sometimes also referred to as“sunstruck or “light struck” flavour. In general, sunstruck formation inbeer is promoted particularly strongly by light with a wavelength of250-550 nm. In general it can be said, the shorter the wavelength thehigher the rate at which sunstruck flavour is formed.

It is believed that volatile sulphur-containing compounds areresponsible for the sunstruck flavour. These sulphur-containingcompounds are thought to be formed at least in part by reaction of othersulphur-containing compounds with photochemically degraded hopcomponents in the beverage. Extremely small quantities of these sulphurcompounds are sufficient to impart a sunstruck flavour to a beverage andto render it less acceptable for the consumer (cf. for exampleKirk-Othmer, Encyclopedia of Chemical Technology, 4^(th) Ed., Vol. 4,pages 22-63, 1992 and US Patent Application No. 2002/0106422).

The photochemical reaction leading to the sulphur-containing substancesthat cause sunstruck flavour, is believed to be assisted by the presenceof riboflavin. Riboflavin can act as a photo initiator in a beverage andis present in beer in significant quantities. Riboflavin in beeremanates mainly from the malt used herein. To a lesser extent also hopsand the action of yeast during the fermentation can contribute to theriboflavin content of beer (cf. for example “Kinetics of RiboflavinProduction by Brewers Yeast” by Tamer et al., pages 754-756 EnzymeMicrob. Technology, 1988, Vol. 10, December).

In order to solve the sunstruck problem it has been proposed to reducethe amount of riboflavin in the beer (“Sunstruck Flavour Formation inBeer” by Sakuma et al. ASBC Journal). Removal of riboflavin can beaccomplished by decomposition. e.g. by using actinic radiation (U.S.Pat. No. 3,787,587, U.S. Pat. No. 5,582,857 and U.S. Pat. No.5,811,144). The amount of riboflavin present in the beer may also bereduced by treating the beer with absorbent clay (U.S. Pat. No.6,207,208) or by co-fermenting with a combination of yeast andLeuconostoc mesenteroides (U.S. Pat. No. 6,514,542). It has also beensuggested to use immobilised riboflavin-binding protein to removeriboflavin or to add said protein to a beverage to inactivate riboflavin(EP-A 0 879 878). The present light stabilising composition isparticularly effective in preventing the development of sunstruckflavour in beer, especially in beer that is stored in a container thatis transparent to light, particularly a container that is transparent tolight with a wavelength in the range of 330-360 nm, more particularly acontainer that is transparent to a wider spectrum of light within therange of 320-400 nm.

A principal source of the sunstruck flavour in beer is3-methyl-2-butene-1-thiol (3-MBT). The sensory threshold value for thissubstance in water is only a few ng/kg (ppt). 3-MBT is believed to beformed by the reaction between light excited riboflavin (largelyoriginating from the malt component) and the bittering principles inbeer, the iso-α-acids, which originate mainly from hop. The use of thepresent light stabilising composition in an effective amount to inhibitlight induced flavour changes is evident by a reduction in the rate of3-MBT formation by at least 30%, preferably by at least 50%, morepreferably at least 60%, even more preferably at least 70% and mostpreferably by at least 80%. A suitable method for determining thereduction in MBT formation is described in the Examples.

Yet another aspect of the present invention relates to a process for themanufacture of a composition that may suitably be used as an additive toimprove the stability of beverages or foodstuffs against light inducedflavour changes, said process comprising the steps of:

-   -   providing a caramelised feedstock;    -   decolourising said feedstock so as to increase its A_(280/560)        by at least 100%.

Decolourisation of the caramelised feedstock may be achieved by anytechnique known in the art that enables the selective isolation fromsaid feedstock of a light stabilising composition as defined hereinbefore, or that enables selective elimination of the colouringsubstances present in the caramelised feedstock, e.g. by bleaching.Examples of suitable isolation techniques include: treatment with anadsorbent material (e.g. reversed phase sorbents), filtration andchromatography. In one embodiment of the present process thedecolourising is achieved by filtration over one or more filters with acut-off of not more than 30 kDa, preferably of not more than 10 kDa,more preferably of not more than 5 kDa and most preferably of not morethan 1 kDa. In another embodiment, decolourisation is achieved byadsorption of the colouring substances onto a reversed phase sorbent,particularly an alkyl-bonded silica or onto cation exchange resin. Inyet another embodiment, decolourising is achieved by means of liquidchromatography, preferably by means of reversed phase or cation exchangechromatography.

Following caramelisation, the caramelised feedstock may comprise highmolecular products that are hardly soluble in aqueous systems. When usedas such in beverages or foodstuffs that are translucent by nature, thismay give rise to an undesirable haze or cloudiness. Thus, in a preferredembodiment, the present process yields a composition that is essentiallycompletely water soluble, meaning that said process comprises anadditional step of removing and/or solubilising insoluble matter if thisis required to achieve said water solubility. The insoluble matter maysuitably be solubilised by e.g. sonication or by adding solvent.

In the present process, the optional removal or solubilisation ofinsoluble matter is preferably carried out prior to decolourisation. Itis noted that the present invention also encompasses a process whereindecolourisation and removal of insolubles are achieved in a single step,e.g. by filtration.

The present invention also encompasses a process wherein the feedstockcontains caramel in combination with one or more other brewing adjuncts,e.g. malt, malted barley, syrup. Particularly suitable caramels for thepresent process are caramels as defined in the European Union Directive95/45; Purity Criteria concerning Colours for use in Foodstuffs and asdefined in US Food Chemical Codex IV. Accordingly, in a very preferredembodiment, the caramelised feedstock contains at least 50% by weight ofdry matter of brewing adjuncts, including at least 5% caramel by weightof dry matter. More preferably, the feedstock contains at least 10%,even more preferably at least 30% and most preferably at least 50%caramel by weight of dry matter.

Caramel is a complex mixture of compounds, some of which are in the formof colloidal aggregates. Caramel is manufactured by heatingcarbohydrates either alone or in the presence of food-grade acids,bases, and/or salts. Caramel is usually a dark brown to black liquid orsolid having an odour of burnt sugar and a somewhat bitter taste.Caramel is produced from commercially available food-grade nutritivesweeteners including fructose, dextrose (glucose), invert sugar,sucrose, lactose, molasses and/or starch hydrolysates and fractionsthereof The acids that may be used are food-grade sulphuric, sulphurous,phosphoric, acetic and citric acids, and suitable bases are ammonium,sodium, potassium and calcium hydroxides. Salts that may be used includeammonium, sodium and potassium carbonate, bicarbonate, phosphate(including mono- and dibasic), sulphate, and sulphite. Caramel issoluble in water.

Four distinct classes of caramel can be distinguished by the reactantsused in their manufacture and by specific identification tests (seeEuropean Union Directive 95/45 Purity Criteria concerning Colours foruse in Foodstuffs and the US Food Chemical Codex IV):

-   -   Class I: plain caramel, caustic caramel; E 150a. Class I        caramels are prepared by heating carbohydrates with or without        acids, bases or salts, but in the absence of ammonium or        sulphite compounds.    -   Class II: caustic sulphite caramel; E 150b. Class II caramels        are prepared by heating carbohydrates with or without acids or        bases in the presence of sulphite compounds, but in the absence        of ammonium compounds.    -   Class III: ammonia caramel; E 150c. Class III caramels are        prepared by heating carbohydrates with or without acids or bases        in the presence of ammonium compounds, but in the absence of        sulphite compounds.    -   Class IV: sulphite ammonia caramel; E 150d. Class IV caramels        are prepared by heating carbohydrates with or without acids or        bases in the presence of both sulphite as well as ammonia        compounds.

Ammonium compounds that are used in class III and IV caramels includeammonium hydroxide, ammonium carbonate, ammonium hydrogen carbonate,ammonium phosphate, ammonium sulphate, ammonium sulphite and ammoniumhydrogen sulphite. The sulphite compounds are for example sulphurousacid, potassium, sodium and ammonium sulphites and potassium, sodium,ammonium hydrogen sulphites. During the preparation process, food-gradeanti-foaming agents may be used as processing aids.

Of the aforementioned four classes of caramel, ammonia caramel andammonia sulphite caramel are particularly suitable starting material forthe present process. In particular ammonia caramel (class III)constitutes an excellent starting material for the production of a lightstabilising composition according to the invention.

The decolourisation step employed in accordance with this invention doesnot result in a significant removal or elimination of substances thatinhibit sunstruck formation, but merely removes or eliminates substancesthat absorb in the visible area. Thus, the decolourisation largelypreserves the absorption characteristics of the decolourised material atthose wavelengths associated with light induced off-flavour formation.This preservation of, mostly UV-light blocking compounds is bestexpressed by the 280/560 ratio (A_(280/560)). This ratio is used in theEuropean caramel purity guidelines (95/45/EU) and denoted as theextinction ratio. Ammonium sulphite caramel is specified having anA_(280/560) of less than 50. Although, there are no such specificationsset for ammonia caramel, in general it will have an A_(280/560) of lessthan 120. The decolourised caramelised carbohydrate containingcomposition obtained from the present process typically has anA_(280/560) of more than 200, preferably of more than 250, morepreferably of more than 350, more preferably of more than 400, even morepreferably of more than 500 and most preferably of more than 1000.

According to the earlier mentioned EU regulations caramel must have acolour intensity at 610 nm of 0.01-0.6. For ammonia caramel therequirement is that the colour intensity is within the range of0.08-0.36. A description of a method for determining the colourintensity is provided below. The colour intensity of the caramelcontaining feedstock used in the present process preferably exceeds0.01, more preferably exceeds 0.024 on a dry weight basis. In thepresent process, the colour intensity of the feedstock is preferablyreduced by at least a factor 5, more preferably by at least a factor 10and most preferably by at least a factor 20 as a result of thedecolourisation.

The present process will usually produce a considerable yield in theform of the present light stabilising composition. Typically, the yieldof the present process is in the range of 5-90%, especially in the rangeof 10-80%. In a particularly preferred embodiment the present processyields a light stabilising composition in accordance with the presentinvention in a yield of at least 20%.

Another aspect of the invention is concerned with a beverage orfoodstuff that exhibits improved stability towards light induced flavourchanges, wherein the beverage or foodstuff is obtained or obtainable bya method of manufacture that comprises introducing the present lightstabilising composition into said beverage or foodstuff. In particular,the invention relates to such a beverage or foodstuff that contains atleast 0.5 mg/kg preferably at least 1 mg/kg, more preferably at least 3mg/kg and most preferably at least 10 mg/kg of pyrazine derivatives asdefined herein before. In an even more preferred embodiment the beverageor foodstuff obtainable by the present method contains at least 0.5mg/kg, preferably at least 1 mg/kg of a fructosazine selected from thegroup consisting of 2,5-deoxyfructosazine, 2,6-deoxyfructosazine,2,5-fructosazine, 2,6-fructosazine and combinations thereof.

Yet another aspect of the invention relates to a hop containing beveragethat is resistant towards light induced flavour changes, said hopcontaining beverage being characterised by an EBC colour value of lessthan 25, preferably of less than 15, more preferably of less than 12,and a content of the pyrazine derivatives as defined herein before,expressed in mg/kg, that exceeds 0.1× EBC colour value, more preferablyexceeds 1× EBC colour value. Even more preferably, said content exceeds5× EBC colour value, most preferably 10× EBC colour value.

Preferably, the hop containing beverage is a fermented cereal basedbeverage. More preferably, the hop containing beverage is beer, maltliquor, porter, shandy, or another beverage made from or containingextracts of hop. Even more preferably, the beverage is beer, mostpreferably lager beer. In a particularly preferred embodiment, the hopcontaining beverage has a yellow or yellowish colour, i.e. it does nothave a brownish colour associated with the use of significant amounts ofcolouring caramel.

As a result of the addition of a light stabilising amount of the presentcomposition, a hop containing beverage will typically contain at least0.5 mg/kg preferably at least 1 mg/kg, more preferably at least 3 mg/kgand most preferably at least 10 mg/kg of the pyrazine derivatives asdefined herein before. In an even more preferred embodiment, the hopcontaining beverage contains at least 0.5 mg/kg, preferably at least 1mg/kg of a fructosazine selected from the group consisting of2,5-deoxyfructosazine, 2,6-deoxyfructosazine, 2,5-fructosazine,2,6-fructosazine and combinations thereof.

As explained herein before, the benefits of the present lightstabilising composition will be particularly apparent in light sensitiveproducts that have been packaged in containers that are transparent tolight with a wavelength of less than 500 nm, especially less than 400nm, e.g. green, clear and blue glass. Consequently, in a preferredembodiment, the present hop containing beverages is bottled in green,clear or blue glass, especially in clear or green glass.

Methods

Solids Content

The solids content of a material is determined by drying a sample upon acarrier composed of pure quartz sand that passes a No. 40 but not a No.60 sieve and has been prepared by digestion with hydrochloric acid,washed acid-free, dried and ignited. Mix 30.0 g of prepared sandaccurately weighed with 1.5-2.0 g accurately weighed material and dry toconstant weight at 60° C. under reduced pressure 50 mm Hg (6.7 kPa).Record the final weight of the sand plus caramel or decolourisedcaramel. Calculate the % solids as follows:${\%\quad{solids}} = {\frac{\left( {w_{F} - w_{S}} \right)}{w_{C}} \times 100}$where

w_(F)=final weight of sand plus caramel

w_(S)=weight of sand

w_(C)=weight of caramel initially added

Colour Intensity

For the purpose of this specification, Colour Intensity of a certainmaterial is defined as the absorbance of an 0.1% (w/v) solution ofsolids in water in a 1 cm quartz cell at 610 nm. If necessary, pH of thesolution is adjusted to between 4 and 7.

Procedure

Transfer an amount of material equivalent to 100 mg solids into a 100 mLvolumetric flask, dilute to volume with water, mix and centrifuge if thesolution is cloudy. Determine the absorbance of the clear solution in a1 cm quartz cell at 610 nm with a suitable spectrophotometer previouslystandardized using water as a reference. Calculate the Colour Intensityof the material as follows:${{Colour}\quad{intensity}} = \frac{A_{610} \times 100}{\%\quad{solids}}$Determine % solids as described under Solids content.Classification/Absorbance Ratio

For the purposes of this specification, Absorbance Ratio of a materialis defined as the absorbance of an 0.1% (w/v) solution of solids inwater at 280 nm divided by the absorbance of the same solution at 560nm. If necessary, pH of the solution is adjusted to between 4 and 7.

Procedure

Transfer an amount of material equivalent to 100 mg solids into a 100 mLvolumetric flask with the aid of water, dilute to volume, mix andcentrifuge if solution is cloudy. Pipet a 5.0 mL portion of the clearsolution into a 100 mL volumetric flask, dilute to volume with water,and mix. Determine the absorbance of the 0.1% (w/v) solution in a 1-cmcell at 560 nm and that of the 1:20 (v/v) diluted solution at 280 nmwith a suitable spectrophotometer previously standardized using water asreference. (A suitable spectrophotometer is one equipped with amonochromator to provide a bandwidth of 2 nm or less and of such qualitythat the stray-light characteristic is 0.5% or less.) Calculate theAbsorbance Ratio by first multiplying the absorbance units at 280 nm by20 (dilution factor) and by dividing the result of the multiplication bythe absorbance units at 560 nm.

EBC Colour

EBC recommended method (European Brewery Convention, Analytica, 1987),whereby absorbance of light is measured at 430 nm in a 1 cm quartzcuvette, against water as the reference. The absorbance value measuredis multiplied by an empirically derived factor of 25, to give a colourvalue in terms of EBC colour units. EBC=A₄₃₀×25.

EXAMPLES Example 1

A light stabilizing composition according to the present invention wasprepared from caramel (type D35 ex Devolder S.A.-N.V.) as follows: 20gram liquid caramel (60-80% dry wt. solid) was dissolved in 200 mLdistilled water and ultrafiltered using a Millipore Amicon® series 8000(model 8400, 400 mL) stirred cell, equipped with a Millipore® YM10regenerated cellulose ultrafiltration membrane (10,000 nominal molecularweight limit, diameter: 76 mm, cat. no. 13642).

150 mL of filtrate was collected and applied to a 70 g, 5×6.5 cm C18-RPSPE bed (Supelco® LC-18 material) that had been conditioned with 50%(v/v) ethanol/water and percolated with 200 mL distilled water beforeusage. After elution of 150 mL distilled water was applied to the columnand another 50 mL was collected. The collected fractions werefreeze-dried before usage.

Example 2

An LC-PDA analysis was performed to identify the substances that aremainly responsible for the UV absorption characteristics of the lightstabilising composition described in example 1.

Methodology:

-   -   Waters Alliance® 2690 HPLC system with Waters® Diode array 996        detector, scanning between 210-400 nm, Millennium 32 software    -   Prevail® Carbohydrate ES (5 μm, 250×4.6 mm) column from Alltech        (cat no. 35101)    -   Isocratic, 40 minute run-time, flow-rate 0.5 ml/min    -   Solvents: 75% Acetonitrile (Sigrna-Aldrich, cat no: 34998), 25%        (v/v) aqueous solution of formic acid (Milli-Q plus water        adjusted to pH 3 with formic acid (98-100%), ACS reagent ex        Riedel-de Haën)    -   Sample temperature: 5° C.    -   Column temperature: 25° C.    -   Degassing: Continuous    -   Samples prepared by 1:1 (v/v) dilution with acetonitrile and        then filtered prior to analysis (PVDF 0.45 μM syringe filters)

In order to determine the accurate masses of components 1 and 2, adecolourised caramel was injected onto an LC-electrospray-ToF-MS(positive mode) using an amino-based analytical column. A solution of 70mg/L polyalanine in methanol was used as the lockmass (the internalcalibrant). The elemental composition for both compounds was found to beC₁₂H₂₁N₂O₇(=(M+H)⁺).

-   Data 2,6-deoxfructosazine    1-[6-(2,3,4-trihydroxy-butyl)-pyrazin-2-yl]-butane-1,2,3,4-tetraol:

Mass found: 305.1353

Mass calculated: 305.1349

Δmass: 1.3 ppm

-   Data 2,5-deoxyfructosazine    1-[5-(2,3,4-trihydroxy-butyl)-pyrazin-2-yl]-butane-1,2,3,4-tetraol:

Mass found: 305.1346

Mass calculated: 305.1349

Δmass: −0.8 ppm

Example 3

The light stabilising properties of a caramel derived compositionaccording to the invention were assessed by adding the light stabilisingcomposition described in Example 1 to Heineken® pilsner (theNetherlands) in dosages of 0.5, 1.0 and 2.0 g/L (dry weight). Thecomposition was added to freshly brewed beer, which was subsequentlybottled in a 300 mL green glass bottle (Heineken® export, BSN or Rexambottle 35.5 EB-5 GR). Bottling was performed in such a way thatentrapment of atmospheric oxygen in the beer and headspace wasminimised.

The bottles containing the light stabilising composition in theindicated amounts as well as a bottle with a control sample were exposedto simulated sunlight by a Xenon lamp (Atlas Material TestingTechnology). The light dose was 2700 KJ/m² during 60 minutes. Inaddition, the samples containing 1.0 g/L of the stabilising compositionwere illuminated under the same conditions for 2, 8 and even 24 hrs.

The concentration of MBT in the samples can suitably be determined bymeans of the method described by Hughes et al. (Hughes P. S., Burke S.and Meacham A. B. (1997) “Aspects of the lightstruck character of beer”.Institute of Brewing, Proceedings of the 6th Central and South AfricaSection, pp. 123-128).

Analyses of the aforementioned samples showed that the MBT concentrationin the samples containing the light stabilising composition wassignificantly lower than the MBT concentration found in the controlsample.

The above graph also shows that the effectiveness of the present lightstabilising composition increases with increasing exposure to light (see% reduction of 1.0 g/L sample as function of light exposure time).

The effect of the stabilising composition according to Example 1 on thecolour of the aforementioned beer samples was determined by measuringthe EBC colour value and the A_(280/560) absorption ratio using themethod described herein before. In addition, the same parameters wereanalysed for beer samples that contained the caramel starting material(original caramel) of Example 1 instead of the treated (decolourised)caramel. The following results were obtained: Colour in EBC (430 nm)ΔEBC ΔEBC Original Decolourised orginal decolourised Dose (g/L) caramelcaramel caramel caramel 0 7.3 6.4* — — 0.5 27.6 7.7 20.4 1.3 1 47.1 8.939.8 2.5 2 81.2 11.5 73.9 5.1*Difference between undosed beers due to batch to batch difference.

A_(280/560) absorption ratio Original caramel Decolourised caramelColour Colour Type caramel A_(280/560) intensity (610) A_(280/560)intensity (610) A 40 0.122 1941 0.002 B 38 0.083 1043 0.005 C 27 0.228568 0.003Caramel A: Caramel color No. 300 ex D. D. WilliamsonCaramel B: Caramel color No. 310 ex D. D. WilliamsonCaramel C: Type D35 ex Devolder S. A.-N. V.

Example 5

The absorption characteristics of the light stabilising compositiondescribed in Example 1 were compared with those of the 2 constituents(2,5- and 2,6-deoxyfructosazine) that were deemed to be largelyresponsible for the UV-absorption properties of said composition around280 nm (see Example 2)

Samples were prepared as follows: An amount of material equivalent to100 mg solids was transferred into a 100 mL volumetric flask with theaid of water, followed by dilution to volume, stirring and centrifugingif the solution is cloudy. Subsequently, a 5.0 mL portion of the clearsolution is pipetted into a 100 mL volumetric flask, diluted to volumewith water, and stirred.

The absorbance of the samples thus prepared was measured in a 1-cmquartz cell at 280 nm with a suitable spectrophotometer that waspreviously standardized using water as reference. A suitablespectrophotometer is one equipped with a monochromator to provide abandwidth of 2 nm or less and of such quality that the stray-lightcharacteristic is 0.5% or less.

The absorption curves for 2,6-deoxyfructosazine, 2,5-deoxyfructosazineand decolourised caramel samples were determined as follows. The spectrawere normalised on the highest absorption in the 250-300 nm area(figures). From the results obtained in Example 2 and the UV absorptiondata it can be calculated that the aforementioned deoxyfructosazinesaccount for about 40% of the UV absorption at 280 nm in this specificdecolourised caramel.

Example 6

Milk is known to develop undesirable flavour changes when it is exposedto light, in particular sunlight. As a result of such exposure milklipid oxidation products such as pentanal and hexanal, anddimethylsulphide are formed. Experiments were conducted to determine theeffect of light stabilising compositions according to the invention onlight induced off-flavour development in milk.

Three 14 mL milk samples were prepared in duplicate in 20 mL SPME (solidphase micro-extraction) vials (flat bottom (23 mm×75 mm) headspace vialwith PTFE lined silicone closure (cat. no. 27199 and 27300) ex Supelco®)in a glove box under a carbon dioxide atmosphere and sealed tight.

Samples A and C: Milk without addition

Sample B: Milk containing 1 g/L of the light stabilising compositiondescribed in Example 1.

Samples A were wrapped in aluminium foil and placed in a sunbox togetherwith the other samples and illuminated for 30 minutes with the Xenonlamp used in Example 3. The light dose applied was 1350 kJ/m². Followingillumination, the samples were analysed by SPME-GC-MS.

The results obtained show that all the milk samples containdimethylsulfide. In both samples B and C the dimethylsulfideconcentration had been reduced after illumination in comparison tosamples A and a significant increase was observed in the concentrationof dimethyldisulfide. The observed increase in dimethyldisulfide contentof sample C was considerably higher than that of sample B.Dimethyldisulfide is a particularly foul smelling substance with anextremely high odour potency.

Example 7

Experiments were carried out to determine the light stabilisingproperties of fructosazines in beer.

MBT Reduction by Synthetic 1,5-deoxyfructosazine

2,5-deoxyfructosazine, synthesised from glucosamine, was dissolved inHeineken® lager beer (0.5 g/L) and illuminated for 12 min. in clearglass vials (40 mL (28×98 mm) with open-top screw cap (phenolic cap,PTFE/silicone septum), cat. no. 27089-U ex Supelco®). All samples wereaccompanied by the appropriate blanks. The samples were analysed on MBTformation. It was found that the addition of the synthetic2,5-deoxyfructosazine in an amount of 0.5 g/L yielded a 70% reduction inMBT formation.

MBT Reduction by Isolated 2,6- and 2,5-deoxyfructosazines.

Both 2,6- and 2,5-deoxyfructosazine were isolated from fermenteddecolourised caramel by preparative liquid chromatography on a Waters®Delta 600 semi-preparative HPLC system with a Waters® Diode array 996detector, scanning between 210-400 nm.

Column details: Prevail Carbohydrate ES (9 μm, 300×20 mm) column fromAlltech® (cat no: 35215) Mobile phase composition: 75% Acetonitrile(Sigma-Aldrich®, cat no: 34998), 25% aqueous solution of formic acid(Milli-Q plus water adjusted to pH 3.0 with formic acid (98-100%), ACSreagent ex Riedel-de Haën) running isocratic at a flow-rate of 10 ml/min(40 minutes run-time). Sample temperature: 25° C. Column temperature:25° C.

The samples were prepared by 1:1 (v/v) dilution of the fermenteddecolourised caramel with acetonitrile followed by filtration (PVDF 0.45μM syringe filters) prior to analysis. Fractions collected weresubjected to solvent evaporation (rotary evaporator) and freeze-drying,yielding a 7.5% fraction containing 2,6-deoxyfructosazine and a 4%fraction containing 2,5-deoxyfructosazine. The isolated fractionscontained only very minor concentrations of contaminants.

Both isolates were dosed to Heineken® beer at 250 mg/L in clear glassvials and illuminated for 12 min. It was found that both productsreduced MBT formation by about 60%.

MBT Reduction by Synthetic 2,5-fructosazine.

2,5-fructosazine ex Sigma-Aldrich was added to Heineken® beer at aconcentration of 0.5 g/L. Samples in clear glass vials were illuminatedfor 12 min. The addition of the fructosazine was found to result in areduction in MBT formation of about 70%.

Example 8

Cation Exchange material (Sigma-Aldrich, Dowex® 50WX4-400 strong cationexchange) was brought into the H⁺ form with a 1M aqueous HCl solutionand thoroughly washed with distilled water until the washings wereneutral. To 10 mL solutions containing 5 g of freeze dried decolourisedcaramel, prepared according to example 1, 0, 0.5, 1.0, 2.0 and 4 gramsof the cation exchange material was added. These mixtures were shakenover night and filtered. The filtrate was freeze-dried and the driedsolid material was added at 1 g/L to 300 g of Heineken beer in Heinekengreen bottles and illuminated for 60 min. The EBC colour value of thebeer samples was determined as well as the reduction in MBT contentversus the control sample, using the MBT analysis described in Example3.

The results obtained are presented in the following graphs.

These results illustrate that cation exchange material can be used to(further) decolourise caramel, while retaining a large part of the UVabsorption capacity.

1-36. (canceled)
 37. A composition comprising caramelised carbohydrate,which composition, when dissolved in water at a dry solids content of0.1 wt. %, exhibits: i. an absorption at 280 nm (A₂₈₀) that exceeds0.01; and ii. an absorption ratio A_(280/560) of at least
 200. 38. Thecomposition according to claim 37, wherein A₂₈₀ exceeds 0.05.
 39. Thecomposition according to claim 37, wherein A_(280/560) is at least 250.40. The composition according to claim 37, wherein the compositioncontains at least 10% caramelised carbohydrate by weight of dry solids.41. The composition according to claim 37, wherein the compositioncontains at least 0.5% N-heterocyclic substances.
 42. The compositionaccording to claim 41, wherein the composition contains at least 1.0%N-heterocyclic substances.
 43. The composition according to claim 37,wherein the composition contains at least 0.5% by weight of dry matter,of pyrazine derivatives according to formula (I):

wherein R₁—R₄ independently represent hydrogen; a hydroxyhydrocarbylresidue or an ester of a hydroxyhydrocarbyl residue; or an ether of ahydroxyhydrocarbyl residue; and at least one of R₁—R₄ is ahydroxyhydrocarbyl residue or an ester or an ether thereof.
 44. Thecomposition according to claim 43, wherein the composition contains atleast 1% by weight of dry matter, of the pyrazine derivatives accordingto formula (I).
 45. The composition according to claim 43, wherein thehydroxyhydrocarbyl residue comprises 1-10 carbon atoms.
 46. Thecomposition according to claim 43, wherein the pyrazine derivativecontains at least two hydroxyhydrocarbyl residues.
 47. The compositionaccording to claim 43, wherein the composition contains at least 0.1% ofa fructosazine selected from the group consisting of2,5-deoxyfructosazine, 2,6-deoxyfructosazine, 2,5-fructosazine,2,6-fructosazine and combinations thereof, by weight of dry matter. 48.The composition according to claim 47, wherein the composition containsat least 0.3% of the fructosazine by weight of dry matter.
 49. Thecomposition according to claim 37, wherein the composition isessentially completely water soluble.
 50. The composition according toclaim 37, wherein the composition contains less than 30%, by weight ofdry matter, of components having a molecular weight in excess of 30 kDa.51. The composition according to claim 50, wherein the compositioncontains less than 30%, by weight of dry matter, of components having amolecular weight in excess of 5 kDa.
 52. The composition according toclaim 37, wherein the colour intensity of the composition at 610 nm doesnot exceed 0.024
 53. The composition according to claim 52, wherein thecolour intensity of the composition at 610 nm does not exceed 0.01. 54.The composition according to claim 37, wherein the solids content of thecomposition is at least 10 wt %.
 55. The composition according to claim54, wherein the solids content of the composition is at least 20 wt %.56. The composition according to claim 55, wherein the solids content ofthe composition is at least 30 wt %.
 57. The composition according toclaim 37, wherein the total nitrogen content of the composition, asdetermined by Nitrogen Determination (Kjeldahl Method), Method II (FNP5), is less than 20%, by weight of dry matter.
 58. The compositionaccording to claim 57, wherein the total nitrogen content of thecomposition, as determined by Nitrogen Determination (Kjeldahl Method),Method II (FNP 5), is within the range of 0.1 to 15%, by weight of drymatter.
 59. A method of manufacturing a beverage or a foodstuff that isresistant to light induced flavour changes, said method comprisingintroducing into said beverage or foodstuff a composition according toclaim
 37. 60. The method according to claim 59, wherein the compositionexhibits an absorption at 280 nm (A₂₈₀) that exceeds 0.05.
 61. Themethod according to claim 59, wherein the composition exhibits anabsorption ratio A_(280/560) of at least 250
 62. The method according toclaim 59, wherein the composition contains at least 10% caramelisedcarbohydrate by weight of dry solids.
 63. The composition according toclaim 59, wherein the composition contains at least 0.5% by weight ofdry matter, of pyrazine derivatives according to formula (I):

wherein R₁—R₄ independently represent hydrogen; a hydroxyhydrocarbylresidue or an ester of a hydroxyhydrocarbyl residue; or an ether of ahydroxyhydrocarbyl residue; and at least one of R₁—R₄ is ahydroxyhydrocarbyl residue or an ester or an ether thereof.
 64. Themethod according to claim 63, wherein the composition contains at least1% by weight of dry matter, of the pyrazine derivatives according toformula (I).
 65. The method according to claim 63, wherein thehydroxyhydrocarbyl residue comprises 1 to 10 carbon atoms.
 66. Themethod according to claim 63, wherein the composition contains at least0.1% of a fructosazine selected from the group consisting of2,5-deoxyfructosazine, 2,6-deoxyfructosazine, 2,5-fructosazine,2,6-fructosazine and combinations thereof, by weight of dry matter. 67.The method according to claim 66, wherein the composition contains atleast 0.3% of the fructosazine by weight of dry matter.
 68. The methodaccording to claim 59, wherein the composition is essentially completelywater soluble.
 69. The method according to claim 59, wherein thecomposition contains less than 30%, by weight of dry matter, ofcomponents having a molecular weight in excess of 30 kDa.
 70. The methodaccording to claim 59, wherein the colour intensity of the compositionat 610 nm does not exceed 0.024.
 71. The method according to claim 59,wherein the solids content of the composition is at least 10 wt %. 72.The method according to claim 59, wherein the total nitrogen content ofthe composition, as determined by Nitrogen Determination (KjeldahlMethod), Method II (FNP 5), is within the range of 0.1 to 15%, by weightof dry matter.
 73. The method according to claim 59, wherein thecomposition is introduced into the beverage or foodstuff in an amount ofbetween 0.01 and 1 wt %, calculated on the basis of the amount of drymatter introduced.
 74. The method according to claim 73, wherein thecomposition is introduced into the beverage or foodstuff in an amount ofbetween 0.02 and 0.3wt %, calculated on the basis of the amount of drymatter introduced.
 75. The method according to claim 59, wherein thecomposition is introduced into a bottled beverage.
 76. The methodaccording to claim 75, wherein the composition is introduced into abeverage bottled in green, clear or blue glass.
 77. The method accordingto claim 59, comprising introducing the composition into beer.
 78. Themethod according to claim 77, comprising introducing the compositioninto beer exhibiting an EBC colour value of less than
 25. 79. The methodaccording to claim 78, comprising introducing the composition into beerexhibiting an EBC colour value of less than
 15. 80. A process for themanufacture of a composition that may suitably be used as an additive toimprove the stability of beverages or foodstuffs against light inducedflavour changes, said process comprising the steps of: a) providing acaramelised feedstock; and b) decolorising said feedstock so as toincrease its A_(280/560) by at least 100%.
 81. Process according toclaim 80, wherein the feedstock is subjected to a filtration step. 82.Process according to claim 80, wherein the feedstock contains at least50% by weight of dry matter of brewing adjuncts, including at least 5%caramel by weight of dry matter.
 83. Process according to claim 82,wherein the feedstock contains at least 10% caramel by weight of drymatter.
 84. Process according to claim 83, wherein the feedstockcontains at least 30% caramel by weight of dry matter.
 85. Processaccording to claim 82, wherein the caramel is ammonia caramel, sulphiteammonia caramel or a combination thereof.
 86. Process according to claim80, wherein the colour intensity of the feedstock at 610 nm exceeds0.01.
 87. Process according to claim 86, wherein the colour intensity ofthe feedstock at 610 nm exceeds 0.024.
 88. Process according to claim80, wherein the colour intensity of the feedstock is reduced by at leasta factor 10 as a result of the decolouration.
 89. Process according toclaim 80, wherein the yield of the process is in the range of 5-90%. 90.Process according to claim 89, wherein the yield of the process is inthe range of 10-80%.
 91. A beverage or foodstuff that is resistant tolight induced flavour changes, wherein the beverage or foodstuff isobtained by a method according to claim
 59. 92. A hop containingbeverage that is resistant to light induced flavour changes, saidbeverage being characterised by an EBC colour value of less than 25 anda content of the pyrazine derivatives as defined in claim 43, expressedin mg/kg, that exceeds 0.1× EBC colour value.
 93. Beverage according toclaim 92, having an EBC colour value of less than
 15. 94. Beverageaccording to claim 92, wherein the beverage contains at least 0.5 mg/kgof pyrazine derivatives according to formula (I):

wherein R₁—R₄ independently represent hydrogen; a hydroxyhydrocarbylresidue or an ester of a hydroxyhydrocarbyl residue; or an ether of ahydroxyhydrocarbyl residue; and at least one of R₁—R₄ is ahydroxyhydrocarbyl residue or an ester or an ether thereof.
 95. Beverageaccording to claim 94, wherein the beverage contains at least 1 mg/kg ofthe pyrazine derivatives.
 96. Beverage according to claim 92, whereinthe hydroxyhydrocarbyl residue comprises 1-10 carbon atoms.
 97. Beverageaccording to claim 92, wherein the hydroxyhydrocarbyl residue comprisesat least two hydroxyl groups.
 98. Beverage according to claim 92,wherein the pyrazine derivative contains at least two hydroxyhydrocarbylresidues.
 99. Beverage according to claim 92, wherein the beveragecontains at least 0.5 mg/kg of a fructosazine selected from the groupconsisting of 2,5-deoxyfructosazine, 2,6-deoxyfructosazine,2,5-fructosazine, 2,6-fructosazine and combinations thereof. 100.Beverage according to claim 99, wherein the beverage contains at least 1mg/kg of a fructosazine selected from the group consisting of2,5-deoxyfructosazine, 2,6-deoxyfructosazine, 2,5-fructosazine,2,6-fructosazine and combinations thereof.
 101. Beverage according toclaim 92, wherein said beverage is bottled in green, clear or blueglass.